Those of us who scan the shores of the North Atlantic are privileged to occasionally encounter that most pulchritudinous of pelagic birds, the Northern Gannet. This seabird in the Family Sulidae is kin to the booby and lethal to any fish foolish enough to feed close to the ocean’s surface; the daring plunge dives of gannets seem death-defying but, thanks to physiological adaptations, the only threat involved is to their prey.

Diving Petrels are short, compact birds with very dense plumage. The tail and wings are both short, the latter being rather paddel-like presumably an adaptation to propulsion under water. Primarily coastal rather than pelagic. Seen at sea either singly or in small groups. At rest, float high on the water. In flight, whirr along in straight lines close to the water, traveling straight through waves without hesitation. Wing beats faster than Little Shearwater. When disturbed either dive or make a short flight then dive. Strokes underwater resemble those of alcids, bending the wings at the carpal joint rather than flapping like penguins. Sadly, easily attracted to lights and will travel down the beam of a torch or flashlight sometimes fatally dashing themselves on the ground. Also tend to fly into flames! Hence the Falkland Island name - 'Firebirds'....

The Diving Petrels display a remarkable lack of morphological diversity and three of the four recognized species are monotypic. Murphy considered exsul (the Kerguelen or Subantarctic Diving-petrel) a full-species but more recent biochemical studies include exsul within urinatrix. Sympatric nesting of P. georgicus and P. urinatrix without interbreeding argues strongly for seperate-species status. Not thought to travel far from nesting grounds although adults may vanish for several weeks following the fledging of the young, presumably to undergo a period of molt.